function cellIndex = CalcCellUnstruct(mesh)
nCell = mesh.iDimensions(3);
cellIndex = cell(nCell,1);

iNode = 1;
for iCell = 1:nCell
    cellIndex{iCell} = ...
        mesh.cell.cell2Node(...
        iNode:iNode + mesh.cell.nodeNumberOfEachCell(iCell)-1 ...
        )+1;
    iNode = iNode + mesh.cell.nodeNumberOfEachCell(iCell);
end